The present invention relates to apparatus for removing large deposits of minerals or salt, called "salt mushrooms", formed in water bodies having high concentration of salts, such as in the Dead Sea; and the invention is therefore described below with respect to this application.
The Dead Sea is a very important source of potash, bromine and other chemicals, which are removed by forming solar evaporation ponds in order to increase their concentration by solar evaporation of water. However, the salts precipitate out in the form of large solid bodies, called "salt mushrooms". These generally have relatively large bases fixed to the water bed, more slender trunks rising to the water line, and then very large, mushrooming heads which can rise above the water line. These solid bodies reduce the rate of water flow, and their large mushrooming heads shade the water from the solar radiation, thereby decreasing the rate of evaporation of the water produced by the solar radiation.
Various techniques have been proposed for removing these salt mushrooms. However, conventional dredging operations which are generally efficient when removing mud and other relatively soft materials, are not efficient, and usually not even effective, when clearing away these salt mushrooms. Thus, in the zones of the water body not occupied by a salt mushroom, the power requirements for the dredging apparatus are very low, but when the dredging apparatus engages one of these salt mushrooms, an extremely high load is imposed on the apparatus.